I am not good at maths but very passionate about physics (I know is sad). I am trying to imagine how strong (or weak) the force of gravity is, so I have this imaginary experiment: [BWe have to stones of, let's say, one kilo each floating in a void, separated by let's say one meter. In absence of any other influence would gravity be strong enough to make them move towards each other. If so, would the movement be perceptible for a human being (a massless human being!). As you can see is not about the numbers, it is mor an effort to visualize. Thanks everybody this forum is fantastic!